DISORDERS OF THE THYROID GLAND IN INFANCY, …

In addition to a decreased peripheral T3 production, the low T3 syndrome of NTI may also be caused by stimulated thyroid hormone degradation due to induction of D3 in different tissues. Pathological expression of D3 may be so high that this results in a state of consumptive hypothyroidism with low serum (F)T4 and T3 and very high rT3 levels. ................
................